The extraction of oil and gas (“O&G”) generates large volumes of contaminated water that is referred to in the O&G industry as “produced water”. Most produced water is contaminated with inorganic salts, metals, organic compounds, and other materials. The most abundant hydrocarbons in produced water include semivolatile organic compounds (“SVOCs”) and volatile organic compounds (“VOCs”). Volatile organic compounds typically include dissolved benzene, toluene, ethylbenzene, and xylenes, collectively referred to as “BTEX”. Other organic constituents in produced water include organic acids, oils, paraffins, and waxes. Volatile inorganic constituents include hydrogen sulfide.
In 1995, the volume of produced water generated from onshore wells throughout the United States of America (“US”) was approximately 17.9 trillion barrels. Normal disposition of produced water is by reinjection into deep rock formations. O&G companies pay to have produced water transported to disposal sites for reinjection. This expensive and time-consuming activity can represent 10 percent of the total cost of hydrocarbon production. Otherwise, regulations require that produced water be treated before it is released into surface water or reused. Current methods for treating produced water are expensive.